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Tesla Deploys Over 300 Powerwalls To Give Hawaiian School Kids AC (electrek.co)
Fred Lambert reports via Electrek: As part of a state initiative, Tesla deployed over 300 Powerwalls in schools to cool down hot classrooms in Hawaii. Hawaii has a problem with hot temperatures in public classrooms that is affecting students negatively. The problem was so significant that the Hawaii State Department of Education had to intervene. They put together a $100 million fund, which has already helped cool down 1,190 classrooms to date, with contracts set for more than 1,300 classrooms, according to The Garden Island. In order to roll out the program without significantly increasing energy costs for public schools, they partnered with Tesla to pair Powerwalls with solar power to reduce the impact of running the air conditioners in classrooms across the state. It also resulted in an interesting learning opportunity about renewable energy and energy storage for students.
well that only equals $40k per classroom :) Air conditioners + solar panels + batteries + labour
It's not a typo if you understood the meaning!
Heat lags peak solar by several hours. Hawaii's grid can't absorb the excess generated at nonn, and strains to supply the need as consumption ramps up just as solar is starting to fall. Some storage to time shift the produced solar power by a few hours is pretty much mandatory, once solar starts to be a large fraction of the total supply. You also need the storage to smooth out sudden dips likes a storm blowing in. Solar production can drop by 80% in a fraction of an hour. That's not a problem if solar is only a few percent of your energy mix, but it can lead to grid instability if the solar is meeting nearly 100% of the total demand at noon, and the conventional power plant is idling near zero output. Fossil fuel plants take time to ramp up. Battery storage (or other grid scale storage) is mandatory for a stable supply once solar (or solar and wind) become a large percentage of total supply.
People don't realize that Hawaii doesn't just have one electric grid. It has one for each island with a low capacity level on each one. The issue now, and how valid depends on how much trust you put into the utility, is that there is so much solar currently connected there are serious issues of grid stability. It was built with generators with slow response times and now you have MW of power that flash on and off with a passing cloud. Someone had to put a surge system in, not sure the schools are the best ones though.